The present disclosure generally relates to systems and methods for acquiring data from a subject and, more particularly, to systems and methods for gathering and analyzing information about the subject's eye movements to determine or predict a state of the subject, including conditions such as hypoxia.
Human brain function is highly vulnerable to hypoxic insults. Hypoxia impairs vision, cognition, motor control, and can cause severe incapacitation and death. Reports on the effects of hypoxia on visual function (i.e. dark adaptation, central brightness contrast, color vision, and central acuity) have been confounded by subjective and environmental factors (i.e. changes in ambient light level and non-compliance by flight crews in accurately reporting physiological disabilities such as color blindness). The few studies that have addressed the effects of hypoxia on objective oculomotor metrics, such as saccadic velocity, have obtained inconsistent results. The question of whether hypoxia modulates oculomotor metrics therefore remains open.
Acute hypoxia, defined as decreased availability of oxygen in the body's tissues that can lead to dyspnea, rapid pulse, syncope, visual dysfunction, and mental disturbances such as delirium or euphoria, is one of the most serious single hazards in military and civil aviation. Thus, international organizations such as the US Federal Aviation Administration and the European Aviation Safety Agency recommend hypoxia training (i.e. performance training while reducing oxygen availability to the trainee) as a mandatory part of flight and cabin crew instruction. Altitude chamber training—a well-established method to train aircrews to recognize early symptoms and signs of hypoxia—has not eliminated in-flight hypoxic incidents, however. A complicating factor is that there are wide individual differences in tolerance to acute and chronic exposures to reduced oxygen environments.
Early and objective detection of the physiological effects of hypoxia can preempt these symptoms, and is critical to prevent catastrophes in civil and military aviation. Considering the above, there continues to be a clear need for rapid, accurate, and non-invasive individualized systems and methods for detecting the presence or onset of hypoxia.